Carburetor for internal-combustion engines



Dec. 19, 1922. 1,439,573. F. S. 0 R E M.

CARBURETOR FOR INTERNAL COMBUSTION ENGINES.

FILED DEC-13.1919.

Inventor:

Frederick Straflner Orem,

Patented Dec. 19, 1922.

UNITED STATES FREDERICK STRATTNER mum, on BALTIMORE, MARYLAND.

CABBURETOR FOR INTERNAL-COMBUSTION ENGINES.

Application fiIedDecember 13, 1919. Serial No. 344,529.

To all whom it may concern:

Be it known that I, FREDERICK STRATTNER OREM, a. citizen of the United States, and a resident of Baltimore, Maryland, have in vented certain new and useful Improvements in Carburetors forInternal-Combustion Engines, of which the following is a specification.

An object of the invention is to provide a carburetor for internal combustion engines which will require no adjustments to meet changes in atmospheric and climatic conditions.

My object further is to provide a carburetor in which the flow of hydrocarbon oil will be due to gravity, and the suction of the 7 engine to cause the oil to flow to the mixing chamber. I alsoaim to provide such a construction that the fuel oil will be thoroughly atomized and mixed with the air, this condition of the fuel being necessary with the grades of oil used at the present time.

A further object of the invention is to furnish a carburetor that will supply rich mixture when needed and lean mixture when this is required.

In carrying out my invention I dispense with the float as now employed in atomizing types of carburetors.

Other objects of the in vention will appear from the following description.

In the drawings 2- Figure 1 is a central sectional view of the carburetor.

Fig. 2 is a sectional view of the main valve and associated parts.

Fig. 3 is a bottom plan view of the main valve."

In these drawings 1 indicates a chamber, which is made up of acylindrical outer casing having within-it and coaxially disposed thereto, a valve casing or cylinder 2, which is separated from the outer casing by an annular space, 3 forming the space in which the air and fuel are initially brought together. The fuel is fed to this chamber through ports 4 arrangei'l at different hei hts in the wall of the inner cylinder and these ports are. controlled by a piston valve 5 of cylindrical form fitted to slide in the inner casing or cylinder 2. so that the ports are uncovered one after the other as the piston rises. This piston. valve has a reduced lower end carrying a needle valve 6 controlling the inlet conduit 7 for the oil which comes from a supply elevated in respect to the highest point of the mixing valve. The piston valve 5 has the upper end of its stem provided with an enlargement or head 8 upon which is screw threaded at 9 the main mixing valve 10. This is of conical form at its upper part and it is provided with a skirt 11 fitted to slide within the upperpart of the casing l. Surmounting this casing 1 is the secondary mixing chamber 1", which is secured thereto by the screws 12 passing through the flanges of these parts.

The secondary mixing chamber is enlarged at its lower end 11 into somewhat of globular shape and at its smaller-upper end 11 which is cylindrical it terminates in a flange by which it is attached to the engine intake.

The upper end or throat 11" has the throttle valve 12 pivoted within it.

Reverting tot-he main mixing valve this is provided with a central nozzle-like-opening 13 leading from a primary mixing chamber 14 to which air or a mixture of air and oil is supplied through the converging nozzlelike openings, 15,from the chamber 3. This chamber 14 is also supplied with mixture through the interior nozzle 16, leading from another primary mixing chamber 17 to which the air and fuel is fed through ports 18. Oil is fed to the chamber 17 through a fine port 19 in the nozzle 20 screwed into the upper end of the stem of the piston valve 5, the oil being conducted to the minute port through a passage 21 extending through the piston'valve and its stem and opening at its lower end into the oil space 22 below the piston valve.

The skirt of the main mixing valve is provided with ports 23 which are wide at the bottom and narrow at the top, the-intermediate widths of these openings being graduated from the narrow to the wide ends, so that as the valve lifts there will be a gradual increase of the area of the o enings f 7 presented for the passage of the alrifroni the chamber 3 to the secondary mixing chamber 1"". These openings as shown in Fig. 3 are flared inwardly and instead of Further, these walls are wide at the top as at 21, Figs. 2 and 3, and narrow at the bottom, whereas as before stated, the openings are narrow at the top, measured in a circumferential direction and wide at the bottom. The walls between the openings form vanes against which the current of air and fuel strikes as it issues from the valve, and thus a rotary motion is given to the valve which will cause a swirling motion to be imparted to the air and fuel issuing into the secondary mixing chamber 1 and cause a thorough intermingling of the air and oil. WVhen the main valve is open only slightly the air rushing through the openings in the valve will act on the upper wide part of the vanes and will turn the valve despite the fact that only a part of the area of the vane is available to be acted on by the air and fuel, this bein' the larger area of the vane at, the top. 1 s the main valve opens more and more, a greater area of opening and a comparatively lesser area of vane wall will be added and the valve will be rotated at a proper calculated speed.

\Vhen the carburetor is not working it will be in the condition shown in Fig. 1, the main mixing valve 10 and piston valve 5 being down and the needle valve resting on its seat and cutting off the gravityfeed of oil to the chamber 22. Supposing the throttle valve to be partly opened for starting the engine, thesuction of the engine will lift the main mixing valve 10 together with the piston valve 5 and the needle valve and fuel will feed by gravity into the space 22, and thence through the conduit 21 to the minute port 19 and to the mixing chamber 17 within the upper end of the stem of the piston valve, where it will mix with air drawn in from the chamber 3 through the jet openings 18 and the mixture thus formed will pass through the nozzle 16 to the chamber 14 where it is broken up and mixed with air drawn througlfports 15 and from here the mixture passes through nozzle 13 into the secondary mixing -chamber 1 where it is further broken up by the swirling air currents issuing from the rotary main mixing valve 10. The action just described takes place in starting or idling.

When the throttle valve is opened further the suction or lessened pressure caused by the engine will raise the main mixing valve higher together with the piston valve 5 and thus the ports 4 will be opened in succession as the piston valve progresses upwardly and fuel will flow bygravity through these ports 4 into the space within casing 1 and at the same time air will be drawn through the lower casing 25 past the choke valve 26 and this air with the fuel issuing through the ports 4 will pass through ports 23 in the mixing valve revolving. it and causing intimate mixture of the oil and air because of the swirling motion imparted thereto and because of the points of dis charge into the secondary chamber being subject to constant change.

The upward travel of the mixing valve will vary in degree with the speed of the engine and this is true also of the piston valve 5 and the uncovering of more or less of the ports 4.

The upward movement of the main mix ing valve will be limited by the stop shoulders 5', 5". I

The various degrees of speed of the engine produce the same results in the quantity of the mixture by raising or lowering the mixing valve 10. The varying conditions are automatically met by reason of this self adjustment.

Since the suction is not directly depended upon to cause the fuel to flow to the chamber 3 it will be obvious that as soon as the ports 4 are uncovered the oil will flow by gravity to the said chamber. This will give the correct amount of oil for all speeds by the height to which the piston valve 5 is lifted by opening ports 4.

The ports 13, 15, 18, will relieve back pressure when the engine runs in reverse direction. In other words, these ports leading back to the chamber and the main air inlet of the lower casing will act as a relief.

The oil chamber 22 will act as a dash pot and permit needle valve to seat itself without jar or shock. As the main mixing valve rises and increases the area of opening of the graduated ports therethrough more air will be admitted and the mixture will be lean. whereas when the mixing valve is lowered and the graduated ports present less area of opening the mixture will be richer.

, 'When the choke valve is closed and the engine is operated the fuel is delivered through the ports 21 by gravity which is equivalent to priming the engine, this being essential in cold weather and also in saving the starting mechanism. From the above, it will be observed that the mixing valve is suspended or of a floating character when the engine is in operation, the only factor controlling the valve being the pull of the engine.

When the speed of the engine increases, the valve rises and when the speed is further increased to its full capacity the valve rises to its upper limit.

The casing is formed in three sections bolted together and the inner cylinder in which the pistonvalve works is formed with the lower section being attached to the back wall thereof. The vclocity='of the air is not so great when the valve first rises, and hence I make the vanes so that they will be acted on with a maximum effect by the air and they are therefore formed extended at their upper ends, where they are first exposed, as the valve rises.

The upper chamber 1* is made separate so that it-can be machined on its interior, as a smoothinterior is necessary.

What I claim is:

l 1. In a carburetor, a mixing chamber, a

cylindrical casing depending therefrom having an air inlet at its lower end, a fixed cylinder coaxially arranged within said cylindrical casing and open at its upperend and having a fuel receiving space, and an admission portat its lower end, said cylinder having ports in its wall at different heights, a

substantially cylindrical floating mixing valve slidably mounted in the upper portion of said cylindrical casing and having 0 enings in its wall, adapted to be uncovere by upward movement of the valve, said valvehaving a centrally disposed fuel discharge port, a piston valve having its upper end connectbd with the mixing valve to move therewith as one body, and its lower end slidably located within said fixed cylinder and cooperating with the ports in the wall thereof, said piston valve having a lengthwise passage' communicating with the central port of the mixing valve and with the fuel receiving space within the lower end of the fixed cyl1nder,'a needle valve carried at the lower end 'of the piston valve and cooperating with the fuel admission port in the cylinder, and means for feeding the fuel,

on its inner side extending vertically between the openings and of gradually decreasing-- width from their upper to their lower ends, a piston in the cylinder controlling the ports thereof, and connected to the rotary valve to rise and fall therewith as one body, and a needle valve carried by the piston to control the inlet of fuel, substantially as'described.

3. In a carburetor, a mixing chamber, a cylindrical air chamber depending therefrom and having an air inlet at its lower end, a fixed cylinder coaxially arranged within said cylindrical casin and open at its upper end and having a uel admission port at its lower end, said cylinder having ports in its wall at different heights, a substantially cylindrical floating mixing valve slidably mounted in the upper portion of said cylindrical casing and having downwardly flaring openings in its walls adapted to be uncovered by upward movement of the valve, said valve having a conical head with a discharge port at the apex, a piston valve having its upper end rigidly connected with the mixing valve, and having its lower end slidably located in said'fixed cylinder, said piston valve having a nozzle at its upper end aligning with the discharge port in the floating mixing valve with a chamber above and a chamber beneath said nozzle, ports leading to both of said chambers from the air chamber, said piston having a lengthwise passage placing said nozzle and adjacent chambers in the iston valve in communication with the fue space in the fixed cylinder beneath -'.the piston valve, and a needle valve on the lower end ofthe piston valve controlling the flow of'fuel to the said space.

- In testimony whereof, I aflix my signature.

" FREDERICK STRATTNER OREM. 

